CW stands for continuous wave, i.e. continuously alternating fields which are emitted from a transmitter to locate metal.
In doing so, it is important whether the primary field is created by sine or pulse waves. The secondary field or the magnetic response to the search object can either be received by a pick-up coil or a decoupled pick-up coil system.
The primary and secondary processes to detect metal are directly linked in terms of time. “Just in time” has the advantage of high detection sensitivity for small metal objects, such as amagnetic detonator components, for instance. CW systems are not compatible with salt water due to the relatively high operating frequency. TR (transmitter receiver) detectors can be fitted with ground balancing (GEB), which hides ground magnetic effects within certain limits.
Advantages:
Low power consumption
Compact electronics
Disadvantage:
Both search devices are designed for cooperative or partially cooperative ground. Both devices can still be used in the case of moderate laterisation. However, they cannot be used for extremely mineralised, highly magnetic ground.
They feature a high level of detection sensitivity, which has been designed particularly highly for the TREX® 210-2 as a handheld mine detector. The search devices differ in terms of the shape of the detector.
The TREX® 204 M has a narrow, hockey stick-type detector, which offers great benefits compared to the plate-like devices, particularly over difficult terrain.
The TREX® 210-2 (HASI system) type is particularly compact and easy to use.
PI stands for pulse induction. They are among the time-controlled (time domain – TD) detectors, which emit strong magnetic pulses.
These electrical pulses induce eddy currents in metal objects, which lead to a secondary field. The procedure’s phenomenon consists of a magnetic echo, which fades over a longer period than the relatively short transmitter pulse. The receiver picks up this echo in a time-controlled way, with a certain de-lay. The timed-Domain function offers advantages and disadvantages compared to “just in time” or CW.
Advantages:
Disadvantages:
The EBINGER GC system, which has been proven thousands of times, stands for ground cancelling, which was patented for EBINGER. Despite the high detection sensitivity, the EBEX® 422 GC can also be used for highly laterised and/or magnetic ground. The search device was designed for long-term use over rough terrain. It features a robust metal construction with tube module technology that can be taken apart.
All components are interchangeable without a subsequent comparison. This makes device servicing easier and ensures availability in the field (field availability). The device is primarily operated using rechargeable, threaded cylinder batteries. Suitable charging technology is available. A ipolar pulse transmitter provides magnetic mine safety.
This is a newly developed high-performance PI system for finding very small metal objects. The detector has been tested by searching for gold nuggets under extreme conditions in the Australian Outback. The tests were completed with great success on the most difficult ground and in extreme temperatures.
The UPEX® ONE-2 offers extremely good ground balancing, which exceeds the effect of many other systems. There are plans to implement the new electronic concept into a mine detector mechanism. The monopolar system is not magnetic mine-safe, which is not a problem for conventional explosive ordnance disposal.